Amanda Berry got on stage at the festival when rapper Nelly brought her out.

Berry didn't speak, but she was smiling, dancing and waving to the crowd.

In an interview with CNN's Erin Burnett, Nelly said it was a moment that will stick with him.

"First of all, that she had a smile on her face, you know, that's one of the most impressive things to me, considering everything that she had been through," he said. "You know, for me to be kind of, like, the first situation that, you know, that she was involved in herself in as far as being out in public, I thought, wow, that was special."

Berry later returned to the stage where Nelly dedicated his hit song, "Just a Dream," to her.

Her appearance came just one day after Ariel Castro pleaded guilty to 937 counts in the case in which he had kidnapped Berry, Gina DeJesus and Michelle Knight.